13 results
Now showing1 - 10 of 13
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Coordinated LTE uplink radio interface scheduling(IEEE, 2013-08-19); ; ; ; Long Term Evolution (LTE) promises substantially higher radio interface throughput compared to 3G access tech-nologies. Sometimes, the bandwidth demands of a time varying LTE user traffic cannot be fulfilled by the existing transport network either due to the limited capacity or because of the inaccuracies involved in the transport link bandwidth dimensioning. This often results in a congestion situation in the transport network. In this study a novel congestion control scheme is introduced for the LTE uplink which works based on the coordination between the limited transport network capacity and the time varying radio interface capacity. The proposed mechanism operates at the eNB where the two network interfaces can be monitored in order to efficiently minimize the congestion situations. The coordination based congestion control algorithm is implemented in an LTE network simulator and its performance is studied for various system load configurations. The simulation results confirm that the proposed algorithm effectively mitigates the congestion and helps achieve an improved uplink application performance. Furthermore, a significant application performance gain is also observed for the downlink applications when the congestion in the uplink is controlled.Publicationtype: Conference Paper123 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Dimensioning of the LTE access network(2013-04); ; ; ; This paper proposes efficient analytical models to dimension the necessary transport bandwidths for the Long Term Evolution (LTE) access network satisfying the QoS targets required by different services. In this paper, we consider two major traffic types: elastic traffic and real time traffic. For each type of traffic, individual dimensioning models are proposed for both the S1 interface and the X2 interface. For elastic traffic the dimensioning models are based on the Processor Sharing models; while for real time traffic the dimensioning models are based on the fundamental queuing models. For validating these analytical dimensioning models, a developed LTE system simulation model is used. Extensive simulations are performed for various traffic and network scenarios. The analytical results derived from the proposed dimensioning models are compared with the simulation results. The presented results demonstrate that the proposed analytical models can appropriately estimate the required performances for different service classes and priorities. Hence they are suitable to be used for dimensioning of the LTE access network with different traffic and network conditions.Publicationtype: Conference Paper130 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Uplink QoS aware multi-homing in integrated 3GPP and non-3GPP future networksFuture wireless networks will consist of a mixed heterogeneous 3GPP and non-3GPP access technologies. The 3rd Generation Partnership Project 3GPP has already facilitated the integration of non- 3GPP access by standardizing the System Architecture Evolution (SAE) where non-3GPP access technologies can co-exist with 3GPP access networks. In such heterogeneous networks though the seamless vertical handovers can be performed between the available access networks, the question still remains whether the Quality of Service (QoS) demands of user applications can be satisfied from QoS unaware non-3GPP access technologies? Within the context of the Open Connectivity Services (OConS) of the SAIL European project[1], this work investigates the effects of the integration of two network types on user Quality of Experience (QoE) in the uplink direction. In order to realize QoS guaranteed service from non-3GPP access technologies, this paper proposes two novel resource estimation and management algorithms. With the help of simulation it is shown that integration of non-3GPP technologies in the existing 4G networks extends the network capacity without compromising the user QoE when the proposed schemes are deployed.© Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2013.Publicationtype: Conference Paper202 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Development of simulation environment for multi-homed devices in integrated 3GPP and non-3GPP networks(2012-12-05); ; ; WLAN has proven itself as the most economical wireless access technology over the time. Its widespread deployment encouraged 3GPP (3rd Generation Partnership Project) to standardize the integration of such non-3GPP access technologies into the existing 3GPP access networks. This opened the door of numerous opportunities for network operators to make use of the economical bandwidth from WLAN in enhancing the end user Quality of Experience (QoE). 3GPP leaves it up to the network operators to do their own research and devise their individual algorithms for this purpose. This raises the need for a proper simulation environment supporting a heterogeneous network of access technologies interconnected according to 3GPP specifications. The goal of this work is to develop a network simulator where 4G LTE (Long Term Evolution) and WLAN co-exist. In addition to standard 3GPP network entities and protocols the simulator also provides other features like multi-homing support, user QoE optimization algorithm as well as network bandwidth resource management techniques.Publicationtype: Conference Paper53 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Adaptive fair radio interface scheduling for LTE networks(IEEE, 2012-12-01); ; ; ; The goal of advanced radio resource management procedures in 4G Long Term Evolution (LTE) is to increase the spectral efficiency beyond an ever achieved level. This objective, however, should be realized by considering an optimal trade-off between system performance and fairness among the users. This work proposes an adaptive packet scheduling mechanism which provides higher spectral efficiency during the times of high system load and a better fairness when enough radio resources are available. The proposed scheme dynamically switches between the well-known Proportional Fair and Blind Equal Throughput scheduling schemes based on the congestion level at the radio interface. Moreover, this work also provides a sophisticated mechanism to estimate the radio interface congestion level to assist the operations of the proposed Adaptive Fair scheduling scheme. The proof of concept is provided with the help of simulation results where the performance of the proposed scheme is evaluated at different radio interface congestion levels.Publicationtype: Conference Paper50 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Dimensioning of the shared transport network for collocated multiradio: LTE and HSDPADue to the coexistence of different generations of mobile radio technologies, more and more mobile network operators are keen on deploying multiple radio technologies on a single cell site and carry their traffic over a common transport network. This paper studies such a collocated multiradio system: collocated LTE and HSDPA. Firstly, we investigate the potential gain by using a shared transport network to carry different radio technologies. Furthermore, this paper proposes analytical models to dimension the shared transport network for elastic traffic (TCP-based traffic) from the different radio technologies, by taking traffic characteristics, QoS requirements of each radio technology and the deployed transport QoS function and packet scheduling into considerations. The proposal for modeling the shared transport network is to apply the M/G/R-PS model per QoS class while taking the potential multiplexing gain of bandwidth sharing among the different QoS classes into account. For validating the analytical models, a system simulation model is developed. The analytical results derived from the proposed dimensioning models are validated by comparing with the simulation results for various traffic and network scenarios. Presented results demonstrate that proposed analytical models are well suitable for dimensioning of the shared transport network. With the help of the proposed analytical models, we analyze the potential sharing gain of such a shared transport system under different traffic loads and mix of different radio technologies.Publicationtype: Conference Paper26 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Open Connectivity Services for future networksThis presented work gives an overview on the FP7 project SAIL, that aims at designing architectures for the Future Networks. The conceptual developments in the work package - Open Connectivity Services (OConS) is the focus of this paper. OConS is proposing an open and flexible architecture framework for handling the connectivities in current and future networks. As exemplary studies, we applied OConS architecture framework to two scenarios: (1) the Mult-P transmission of 3GPP LTE connected with WLAN; (2) the extensions of ICN (Information Centric Networks) supporting Multi-P. They show the flexibility and the openness of OConS, and the benefits expected will be e.g. higher data rates, higher resource utilization and more reliable connectivity.Publicationtype: Conference Paper32 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Performance comparison of PDCP buffer management schemes in LTE systemLong Term Evolution (LTE) provides a new radio technology that allows operators to achieve even higher peak throughputs than HSPA+. One of the LTE system performance optimization point is the PDCP buffer management mainly in the downlink. Per bearer PDCP buffers at eNodeB (eNB) hold DL data before it is transmitted over radio interface. This buffered data also contributes towards X2 traffic volume which influences the required handover completion time during inter-eNB handover events. An efficient buffer management scheme is required to maintain the per-bearer PDCP buffer occupancy to a minimal level without a noticeable degradation in user application performance. This work presents three buffer management schemes for PDCP buffers at eNB and provides a thorough study of their performance for real world scenarios. Through an intensive set of simulations, the effectiveness of proposed PDCP buffer management schemes in achieving an optimal PDCP buffer occupancy is proved. Furthermore, the configuration parameters are suggested to achieve optimum LTE system performance using the proposed scheme.Publicationtype: Conference Paper32 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , LTE system performance optimization by discard timer based PDCP buffer managementLong Term Evolution (LTE) provides a new radio technology that allows operators to achieve even higher peak throughputs than HSPA+. One of the LTE system performance optimization point is the PDCP buffer management mainly at the downlink. PDCP buffers at the eNodeB (eNB) hold user data before it is selected by MAC scheduler for transmission over radio interface. This buffered data also contributes towards X2 traffic volume and required handover completion time during inter-eNB handover events. A buffer management scheme is required to keep PDCP buffer occupancy to a minimal level without a noticeable degradation in user application performance. In other word it should hold sufficient data to optimize the radio performance at Uu interface. This is a challenging issue for the mobile network operator and has to be thoroughly investigated and analyzed. This work suggests a novel buffer management scheme for PDCP buffers at eNB and provides a thorough study of its performance for several real world scenarios. Through an intensive set of simulations, the effectiveness of proposed PDCP buffer management scheme in achieving an optimal PDCP buffer occupancy is proved. Furthermore configuration parameters are suggested to achieve optimum LTE system performance using the proposed scheme.Publicationtype: Conference Paper27 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , User satisfaction based resource allocation in future heterogeneous wireless networksThe widespread use of heterogeneous wireless network technologies and their integration with multi-mode terminals enable users to be associated to the best available networks according to user preferences and application specific requirements. We study a user-centric quality of experience based resource allocation problem with several operators, several types of users and different classes of services. We propose a framework for future short term user-operator contractual vision. We also study the equilibrium solution for the mentioned problem using a game-theoretic approach. Based on experimental measurements, we formulate the utility functions for the users and the operators. Our results are validated through OPNET simulations for different service classes including FTP, VoIP and Video streaming over Long Term Evolution (LTE), and Wireless Local Area Networks (WLAN) technologies. We also implement the IPv6 based flow management for congestion avoidance at inter-operator level, and study the performance of various splitting and non-splitting approaches.Publicationtype: Conference Paper38